title: Clinical relevance of symptomatic superficial-vein thrombosis extension: lessons from the CALISTO study.
abstract: The clinical relevance of symptomatic extension of spontaneous, acute, symptomatic, lower-limb superficial-vein thrombosis (SVT) is debated. We performed a post hoc analysis of a double-blind trial comparing fondaparinux with placebo. The main study outcome was SVT extension by day 77, whether to ≤ 3 cm or > 3 cm from the sapheno-femoral junction (SFJ). All events were objectively confirmed and validated by an adjudication committee. With placebo (n = 1500), symptomatic SVT extension to ≤ 3 cm or > 3 cm from the SFJ occurred in 54 (3.6%) and 56 (3.7%) patients, respectively, inducing comparable medical resource consumption (eg, anticoagulant drugs and SFJ ligation); subsequent deep-vein thrombosis or pulmonary embolism occurred in 9.3% (5/54) and 8.9% (5/56) of patients, respectively. Fondaparinux was associated with lower incidences of SVT extension to ≤ 3 cm (0.3%; 5/1502; P < .001) and > 3 cm (0.8%; 12/1502; P < .001) from the SFJ and reduced related use of medical resources; no subsequent deep-vein thrombosis or pulmonary embolism was observed in fondaparinux patients. Thus, symptomatic extensions are common SVT complications and, whether or not reaching the SFJ, are associated with a significant risk of venous thromboembolic complications and medical resource consumption, all reduced by fondaparinux.
authors.affiliation: Unité Mixte de Recherche/Centre National de la Recherche Scientifique 5558, Faculté de Médecine René Thomas Hyacinthe Laennec, University of Lyon, Lyon, France. al@upucl.univ-lyon1.fr
authors.forename: Alain
authors.initials: A
authors.lastname: Leizorovicz
authors.forename: François
authors.initials: F
authors.lastname: Becker
authors.forename: Andrea
authors.initials: A
authors.lastname: Buchmüller
authors.forename: Isabelle
authors.initials: I
authors.lastname: Quéré
authors.forename: Paolo
authors.initials: P
authors.lastname: Prandoni
authors.forename: Hervé
authors.initials: H
authors.lastname: Decousus
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D000077425:Fondaparinux; D006801:Humans; D015994:Incidence; D010919:Placebos; D011134:Polysaccharides / Q000627:therapeutic use; D020246:Venous Thrombosis / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*
chemical_list: D000925:Anticoagulants; D010919:Placebos; D011134:Polysaccharides; D000077425:Fondaparinux